Accession Number:

ADA045241

Title:

Unsteady Airloads in Separated and Transonic Flow

Descriptive Note:

Conference Proceedings

Corporate Author:

ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE)

Personal Author(s):

Report Date:

1977-07-01

Pagination or Media Count:

275.0

Abstract:

The first session reviewed the prediction and description of the separated flow environment and the essential effects of airframe response on individual aircraft components. These effects may lead to failures of primary or secondary structures when exceeding design stress limits, or design fatigue loads. This is a special concern for military aircraft where flight operation at extreme manoeuvre conditions associated with flow separation frequently occurs. The scope of study included analytical approaches, windtunnel tests, as well as flight test techniques and data evaluation. The second session dealt with flutter, aeroservoelastic instabilities involving coupling with active control systems, and other static and dynamic aeroelastic problems, which can be dangerous flight safety phenomena and which must therefore be predicted with accuracy and prevented. Margins of safety are least in the transonic speed range which is consequently the most critical speed regime. However, no dependable theoretical methods are yet available for predicting unsteady transonic airloads on lifting surfaces and control surfaces. Accurate prediction of the latter becomes more important for active control systems used in load alleviation. In addition to improving analytical confidence, a dependable approach could reduce the cost of aeroelastic model and flight flutter tests.

Subject Categories:

  • Aerodynamics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE